1. Technical Field
The present invention generally relates to parts handling equipment. More particularly, the present invention relates to parts feeding systems. Even more particularly, the present invention relates to parts feeding systems which utilize automated exchangeable parts presentation devices.
2. Background Information
Well known parts handling equipment, and more particularly, parts feeding systems, are integral to the manufacture of a wide array of products. Many different industries--including the automotive, fastener, food, electronics, packaging, pharmaceutical, and plastics--utilize parts feeding systems in product assembly and packaging operations. Bottles, bolts, tablets, connectors, capacitors, and bullet casings are just a few parts which are handled by parts feeding systems. Numerous products, such as tape recorders, cellular telephones, and clocks are manufactured through the utilization of parts feeding systems. A problem associated with parts feeding systems, however, is that they are dedicated manufacturing tools, designed to accommodate parts which are either identical or nearly identical in part size and geometry.
A typical parts feeding system comprises numerous components. First, a storage means, such as a bulk supply hopper or bin is used to store a plurality of parts. A conveyor or other feeder device transfers the parts from the storage means to a parts feeder, where separation, singulation, and orientation of the parts typically occurs. Parts feeders include vibratory bowl feeders, rotary and centrifugal parts feeders, and linear parts feeders. The parts feeding system may include one or more feeder elements for singulation and orientation of the parts moving therethrough. A linear parts feeder, such as a linear belt conveyor or a vibratory in-line feeder may be utilized as the orientation and presentation element. Feeder elements may also include means to reject or divert parts which are not properly oriented. The rejection of improperly oriented parts may be accomplished by various means, including gravity chutes, mechanical barriers, and air pressure. The combination of components so far described are also known as the recirculating feeder components.
One type of parts feeding system features a presentation block, where the parts are presented for final action. The presentation block may include an means for orienting the parts as they move from one end of the block to an opposite end. In this regard, a vibratory driver or a linear belt conveyor may be utilized. The presentation block may also include an escapement for parts singulation. This presentation block may also include pneumatic, and/or optical, and/or electronic sensors. The presentation block may also include a parts diverter for rejecting parts which become improperly oriented as they move along the block. This typical parts feeding system is made up of the recirculating feeder components and a presentation block for each part configuration. However, as parts feeding systems are designed for many different applications, there are numerous combinations of the above components.
The presentation block presents the final positioning of the parts or sets or arrays of parts so that they can be removed, one at a time, from a predefined pick-up point on the presentation block, so that the part or parts can be taken to the next manufacturing operation. Typically associated with known parts feeding systems is a means for detecting the presence or absence of a part at the predefined pick-up point on the presentation block. Detection of parts may be accomplished through various known detecting means, including electronic detectors, photoelectric detectors, and air detectors. Once a part is detected at the pick-up point, the parts feeding system may shut off, so that the part presented at the pick-up point may be removed and taken to the next manufacturing operation. During shut off, generally all feeding elements cease operating. By ceasing operation of all feeding elements in the system, "back up" of parts is prevented, which further facilitates the removal of parts from the block. Typically, a "pick and place" device or a robot is employed to remove the parts from the presentation block. Vision guided robotics are also being successfully integrated into parts feeding systems for the precise orientation of the parts as they are taken to the next manufacturing operation. Adept Technology, Inc., of San Jose, Calif., is a manufacturer of such advanced vision guided robot systems.
As stated above, typical parts feeding systems have limited flexibility because they can only accommodate parts which are either identical or nearly identical in part size and geometry. The limited flexibility of parts feeding systems is most apparent at the orientation component, which is specifically designed for a very specific part size and geometry. While some parts feeders can handle parts which vary minimally in size and shape, parts feeding systems in general have limited flexibility due to the inability to effectively handle different size and shape part configurations.
Over the years, parts feeding systems have evolved to accommodate improved feeding rates. Parts feeding systems utilizing "pick and place" devices or robotics to orient and transfer the parts from the presentation block to the next step in the manufacturing process operate under exceptionally fast rates. As an example, while it is possible to manually exchange one presentation block with a different presentation block so that a different shape and size part can be accommodated in the feeding system, the manual exchange of presentation blocks is a time consuming and therefore expensive practice. Currently, the exchange of presentation blocks requires a set up person to unscrew or unclamp the attached presentation block, and thereafter mechanically attach a different presentation block.
The consumer products marketplace embraces rapid change resulting in a limited market life for many products. This rapid change is most notable in the consumer electronics industry. In order for manufacturers to effectively compete in the consumer products marketplace, new products must be designed and manufactured in compressed time frames. Because the manual exchange of tooling elements, i.e., presentation blocks, is time consuming, manual exchange is often not conducive to industries having rapid production rates and short product development cycles. Manual exchange not only slows production, but the delays associated with the manual exchange of tooling elements also slows the product development cycle and adds additional cost to product development. Furthermore, the introduction of entirely new parts feeding systems as substitutes for existing systems does not provide a practical alternative.
Thus, a need exists for a "flexible" parts feeding system which permits rapid and automated exchange of parts presentation blocks or devices so that different size and shape parts can be handled in the parts feeding system, thereby lowering the product development cycle and reducing costs in the manufacturing process. Until now, the means for this rapid and "flexible" exchange of presentation blocks has not existed.